Fluorescence loss spectrum for detecting cold Rydberg atoms with high sensitivity has been obtained based on lock-in detection of fluorescence of 6 P3/2 state when cooling lasers of the magneto-optical trap are modula...Fluorescence loss spectrum for detecting cold Rydberg atoms with high sensitivity has been obtained based on lock-in detection of fluorescence of 6 P3/2 state when cooling lasers of the magneto-optical trap are modulated.The experiment results show that the signal to noise ratio has been improved by 32.64 dB when the modulation depth(converted to laser frequency)and frequency are optimized to 4 MHz and 6 kHz,respectively.This technique enables us to perform a highly sensitive non-destructive detection of Rydberg atoms.展开更多
Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How st...Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How straw mulching affects the composition and loss of runoff DOM by changing soil aggregates remains largely unclear.Here,a straw mulching treatment was compared to a no mulching treatment(as a control)on sloping farmland with black soil erosion in Northeast China.We divided the soil into large macroaggregates(>2 mm),small macroaggregates(0.25-2 mm),and microaggregates(<0.25 mm).After five rain events,the effects of straw mulching on the concentration(characterized by dissolved organic carbon(DoC)and composition(analyzed by fluorescence spectroscopy)of runoff and soil aggregate DOM were studied.The results showed that straw mulching reduced the runoff amount by 54.7%.Therefore,although straw mulching increased the average DOc concentration in runoff,it reduced the total runoff DOM loss by 48.3%.The composition of runoff DOM is similar to that of soil,as both contain humic-like acid and protein-like components.With straw mulching treatment,the protein-like components in small macroaggregates accumulated and the protein-like components in runoff declined with rain events.Fluorescence spectroscopy technology may help in understanding the hydrological paths of rain events by capturing the dynamic changes of runoff and soil DOM characteristics.A variation partitioning analysis(VPA)indicated that the DOM concentration and composition of microaggregates explained 68.2%of the change in runoff DOM from no mulching plots,while the change in runoff DOM from straw mulching plots was dominated by small macroaggregates at a rate of 55.1%.Taken together,our results demonstrated that straw mulching reduces the fragmentation of small macroaggregates and the loss of microaggregates,thus effecting DOM compositions in soil and reducing the DOM loss in runoff.These results provide a theoretical basis for reducing carbon loss in sloping farmland.展开更多
We study the spatial structure and sympathetic cooling of the bi-component Coulomb crystal(CC),which consists of approximate 450^(9)Be^(+)ions and 450^(40)Ca^(+)ions with a mass ratio of 0.225 in a segmented linear io...We study the spatial structure and sympathetic cooling of the bi-component Coulomb crystal(CC),which consists of approximate 450^(9)Be^(+)ions and 450^(40)Ca^(+)ions with a mass ratio of 0.225 in a segmented linear ion trap.By twodimensional imaging of the bi-component CC,the^(9)Be^(+)ions are found to be surrounded by the^(40)Ca^(+)ions in the radial direction with a separation ratio of~2.0,and the axial length of the^(9)Be^(+)ions occupied area is much larger than that of the^(40)Ca^(+)ions occupied area.Combined with the previous experimental results,the structure of the^(9)Be^(+)–^(40)Ca^(+)CC shows the larger the difference in the mass–charge ratio,the larger the separation between the two species.The comparison of the fluorescence spectra of the^(9)Be^(+)ions in the bi-component CC and the pure CC indicates that the^(9)Be^(+)ions can be sympathetically cooled and stably localized by the laser-cooled^(40)Ca^(+)ions during the recording of the fluorescence spectrum.展开更多
This study proposed the design, fabrication, and assembly of membrane integrity detection instruments in membrane bioreactors (MBR) based on fluorescence spectroscopy. Based on the PARAFAC model, we found that the pea...This study proposed the design, fabrication, and assembly of membrane integrity detection instruments in membrane bioreactors (MBR) based on fluorescence spectroscopy. Based on the PARAFAC model, we found that the peak at 280/335 nm strengthened after membrane breakage. The peak at 340/430 nm reflected the sludge concentration in the MBR and reduced the influence of internal filtration effects on detection. Therefore, we determined that the dual-LED light source excitation detection system can detect tryptophan-like substances at 280 nm (T-peak) and humic acid at 340 nm (C-peak). T-peak was identified as the core index indicating membrane integrity. Moreover, the C-peak is the reference indicator factor for a sensitive response to changes in the sludge concentration. The portable fluorescence instrument exhibited high sensitivity and good feedback accuracy compared to particle counting and turbidity detection, where the log reduction value was greater than 3.5. This overcomes the disadvantage of false alarms in particle counters and is not affected by the position of the pump system. This portable instrument provides a flexible and highly sensitive method for the assessment of industrial membrane integrity.展开更多
Digestive tract tumors acount for 15%and 19.3%of the cancer incidence and deaths,respec-tively.Early detection of digestive tract tumors is crucial to the reduction of global cancer burden.Two-photon excitation fuores...Digestive tract tumors acount for 15%and 19.3%of the cancer incidence and deaths,respec-tively.Early detection of digestive tract tumors is crucial to the reduction of global cancer burden.Two-photon excitation fuorescence lifetime imaging microscopy(TP-FLIM)allows non-invasive,label free,three-dimensional,high-resolution imaging of living tisues with not only histological but also biochemical characterization ability in both qualitative and quantitative way.Benefiting from these advantages,this technology is protmising for clinical diagnosis of digestive tract tumors.In recent years,many efforts have'been made in this field and some remarkable progress has been achieved.In this paper,we overview the recent progress of TP-FLIM-based researches on digestive tract tumor detection.Among them,our latest results on the gastric cancer and esophageal cancer are elaborately depicted.Finally,we outlook and discuss the potential advantages and challenges of TP-FLIM in future clinical applications.展开更多
The influences of Fe2+ on the aggregation behavior of residual hydrophobic modified polyacryamide (HMPAM) in treated oily wastewater were studied by fluorescence spectrum and DLS. The result of I1/I3 showed that the p...The influences of Fe2+ on the aggregation behavior of residual hydrophobic modified polyacryamide (HMPAM) in treated oily wastewater were studied by fluorescence spectrum and DLS. The result of I1/I3 showed that the polarity of hydrophobic domain increased and the size of hydrophobic domain may be decreased with the increasing of Fe2+ in produced water. Fe2+ was helpful for the increase of hydrophobic domain, therefore due to the aggregation degree for HMPAM.展开更多
A novel fluorimetric method for determination of paeonol,an active component of Chinese herbal medicine,is proposed.The method is based on the reaction of paeonol with aluminum ion in pH 4.4 HAc-NaAc buffer to form a ...A novel fluorimetric method for determination of paeonol,an active component of Chinese herbal medicine,is proposed.The method is based on the reaction of paeonol with aluminum ion in pH 4.4 HAc-NaAc buffer to form a fluorescent Al(Ⅲ)-paeonol complex.The maximum excitation wavelength and emission wavelength of the complex were 296 nm and 455 nm,respectively.The fuorescence quantum yield of the complex was determined to be 0.053 at an excitation wavelength of 296 nm.A linear calibration curve covered the concentration range 0.017-1.2μg/mL.The method has been applied to the analysis of paeonol in medicinal crop Cynanchi Paniculati Radix(Xuchangqing),and the results demonstrated that this method can be used for quality evaluation of crude drug Xuchangqing.展开更多
Porous silica nanocapsules with 20% 3-aminopropyltrimethoxysilane (APS)-bound 6-carboxy-fluorescein (APS-fluorescein) and 80% APS molecules adsorbed on the surface
Two novel macrocyclic Schiff base complexes[LnL(PhCOO)(CH3OH)](ClO4)2·(CH3OH)2(Ln=Ho,1;Ln=Er,2),in which L denotes the macrocyclic ligand,were synthesized via condensation of 2,6-diformyl-4-methyl-phenol and 1,3-...Two novel macrocyclic Schiff base complexes[LnL(PhCOO)(CH3OH)](ClO4)2·(CH3OH)2(Ln=Ho,1;Ln=Er,2),in which L denotes the macrocyclic ligand,were synthesized via condensation of 2,6-diformyl-4-methyl-phenol and 1,3-diamino-2-propanol by employing benzoate as the second ligand.Their crystal structures were determined by X-ray diffraction,which showed that both complexes belong to a monoclinic system with space group P21/c.The coordination polyhedron displayed a distorted bicapped trigonal prism with the coordination number of eight.Both complexes efficiently cleaved supercoiled DNA to its nicked circular form.The UV-vis absorption results and ethidium bromide(EB)fluorescence spectra indicated that the complexes bind to CT-DNA in an intercalative mode,with Ksq values to be 11830 and 10560,respectively.展开更多
A metalloporphyrin-based fluorescent sensor was developed to determine the acid value in frying oil.The electronic and structural performances of iron tetraphenylporphyrin(FeTPP)were theoretically investigated using t...A metalloporphyrin-based fluorescent sensor was developed to determine the acid value in frying oil.The electronic and structural performances of iron tetraphenylporphyrin(FeTPP)were theoretically investigated using time-dependent density functional theory and density functional theory at the B3LYP/LANL2DZ level.The quantified FeTPP-based fluorescent sensor results revealed its excellent performance in discriminating different analytes.In the present work,the acid value of palm olein was determined after every single frying cycle.A total of 10 frying cycles were conducted each day for 10 consecutive days.The FeTPP-based fluorescent sensor was used to quantify the acid value,and the results were compared with the chemical data obtained by conventional titration method.The synchronous fluorescence spectrum for each sample was recorded.Parallel factor analysis was used to decompose the three-dimensional spectrum data.Then,the support vector regression(SVR),partial least squares,and back-propagation artificial neural network methods were applied to build the regression models.After the comparison of the constructed models,the SVR models exhibited the highest correlation coefficients among all models,with 0.9748 and 0.9276 for the training and test sets,respectively.The findings suggested the potential of FeTPP-based fluorescent sensor in rapid monitoring of frying oil quality and perhaps also in other foods with higher oil contents.展开更多
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFA0304203 and 2016YFF0200104)the National Natural Science Foundation of China(Grant Nos.61505099,61827824,91536110,and 61975104)the Fund for Shanxi ‘1331 Project’ Key Subjects Construction,Bairen Project of Shanxi Province,China
文摘Fluorescence loss spectrum for detecting cold Rydberg atoms with high sensitivity has been obtained based on lock-in detection of fluorescence of 6 P3/2 state when cooling lasers of the magneto-optical trap are modulated.The experiment results show that the signal to noise ratio has been improved by 32.64 dB when the modulation depth(converted to laser frequency)and frequency are optimized to 4 MHz and 6 kHz,respectively.This technique enables us to perform a highly sensitive non-destructive detection of Rydberg atoms.
基金supported by the National Key Research and Development Project of China (2022YFD1601102)the Key R&D Plan of Heilongjiang Province, China (JD22B002)+1 种基金the Program on Industrial Technology System of National Soybean, China (CARS-04-PS17)the UNDP Project, China (cpr/21/401) and the National Natural Science Foundation of China (41771284)
文摘Straw mulching is a widespread practice for reducing the soil carbon loss caused by erosion.However,the effects of straw mulching on dissolved organic matter(DOM)runoff loss from black soil are not well studied.How straw mulching affects the composition and loss of runoff DOM by changing soil aggregates remains largely unclear.Here,a straw mulching treatment was compared to a no mulching treatment(as a control)on sloping farmland with black soil erosion in Northeast China.We divided the soil into large macroaggregates(>2 mm),small macroaggregates(0.25-2 mm),and microaggregates(<0.25 mm).After five rain events,the effects of straw mulching on the concentration(characterized by dissolved organic carbon(DoC)and composition(analyzed by fluorescence spectroscopy)of runoff and soil aggregate DOM were studied.The results showed that straw mulching reduced the runoff amount by 54.7%.Therefore,although straw mulching increased the average DOc concentration in runoff,it reduced the total runoff DOM loss by 48.3%.The composition of runoff DOM is similar to that of soil,as both contain humic-like acid and protein-like components.With straw mulching treatment,the protein-like components in small macroaggregates accumulated and the protein-like components in runoff declined with rain events.Fluorescence spectroscopy technology may help in understanding the hydrological paths of rain events by capturing the dynamic changes of runoff and soil DOM characteristics.A variation partitioning analysis(VPA)indicated that the DOM concentration and composition of microaggregates explained 68.2%of the change in runoff DOM from no mulching plots,while the change in runoff DOM from straw mulching plots was dominated by small macroaggregates at a rate of 55.1%.Taken together,our results demonstrated that straw mulching reduces the fragmentation of small macroaggregates and the loss of microaggregates,thus effecting DOM compositions in soil and reducing the DOM loss in runoff.These results provide a theoretical basis for reducing carbon loss in sloping farmland.
基金the National Natural Science Foundation of China(Grant No.91636216)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21020200).
文摘We study the spatial structure and sympathetic cooling of the bi-component Coulomb crystal(CC),which consists of approximate 450^(9)Be^(+)ions and 450^(40)Ca^(+)ions with a mass ratio of 0.225 in a segmented linear ion trap.By twodimensional imaging of the bi-component CC,the^(9)Be^(+)ions are found to be surrounded by the^(40)Ca^(+)ions in the radial direction with a separation ratio of~2.0,and the axial length of the^(9)Be^(+)ions occupied area is much larger than that of the^(40)Ca^(+)ions occupied area.Combined with the previous experimental results,the structure of the^(9)Be^(+)–^(40)Ca^(+)CC shows the larger the difference in the mass–charge ratio,the larger the separation between the two species.The comparison of the fluorescence spectra of the^(9)Be^(+)ions in the bi-component CC and the pure CC indicates that the^(9)Be^(+)ions can be sympathetically cooled and stably localized by the laser-cooled^(40)Ca^(+)ions during the recording of the fluorescence spectrum.
基金supported by the Research Agricultural Project of Tianjin(China)(No.JBGG202207)the support of Cangzhou Institute of Tiangong University(China)(No.TGCYY-F-0103)Beijing Nova Program(China)(No.Z201100006820040).
文摘This study proposed the design, fabrication, and assembly of membrane integrity detection instruments in membrane bioreactors (MBR) based on fluorescence spectroscopy. Based on the PARAFAC model, we found that the peak at 280/335 nm strengthened after membrane breakage. The peak at 340/430 nm reflected the sludge concentration in the MBR and reduced the influence of internal filtration effects on detection. Therefore, we determined that the dual-LED light source excitation detection system can detect tryptophan-like substances at 280 nm (T-peak) and humic acid at 340 nm (C-peak). T-peak was identified as the core index indicating membrane integrity. Moreover, the C-peak is the reference indicator factor for a sensitive response to changes in the sludge concentration. The portable fluorescence instrument exhibited high sensitivity and good feedback accuracy compared to particle counting and turbidity detection, where the log reduction value was greater than 3.5. This overcomes the disadvantage of false alarms in particle counters and is not affected by the position of the pump system. This portable instrument provides a flexible and highly sensitive method for the assessment of industrial membrane integrity.
基金supports from the National Key Research and Development Program of China(2017YFC0110200)Program 973(2015CB755502)+4 种基金the National Natural Science Foundation of China(NSFC)(81571724,81701744,81822023)the Natural Science Foundation of Guangdong Province(2014A030312006,2017A 030310308)the Scientific Instrument Innovation Team of Chinese Academy of Sciences(GJJSTD 20180002)the Shenzhen Science and Technology Program(JCYJ20170818164343304,JCYJ20170818155006471,JCYJ20160608214524052,JCYJ20180507182432303)the SIAT Innovation Program for Excellent Young Researchers(201821).
文摘Digestive tract tumors acount for 15%and 19.3%of the cancer incidence and deaths,respec-tively.Early detection of digestive tract tumors is crucial to the reduction of global cancer burden.Two-photon excitation fuorescence lifetime imaging microscopy(TP-FLIM)allows non-invasive,label free,three-dimensional,high-resolution imaging of living tisues with not only histological but also biochemical characterization ability in both qualitative and quantitative way.Benefiting from these advantages,this technology is protmising for clinical diagnosis of digestive tract tumors.In recent years,many efforts have'been made in this field and some remarkable progress has been achieved.In this paper,we overview the recent progress of TP-FLIM-based researches on digestive tract tumor detection.Among them,our latest results on the gastric cancer and esophageal cancer are elaborately depicted.Finally,we outlook and discuss the potential advantages and challenges of TP-FLIM in future clinical applications.
文摘The influences of Fe2+ on the aggregation behavior of residual hydrophobic modified polyacryamide (HMPAM) in treated oily wastewater were studied by fluorescence spectrum and DLS. The result of I1/I3 showed that the polarity of hydrophobic domain increased and the size of hydrophobic domain may be decreased with the increasing of Fe2+ in produced water. Fe2+ was helpful for the increase of hydrophobic domain, therefore due to the aggregation degree for HMPAM.
基金This work was supported by the National Natural Science Foundation of China(Nos.20675025,20975029 and 81173496).
文摘A novel fluorimetric method for determination of paeonol,an active component of Chinese herbal medicine,is proposed.The method is based on the reaction of paeonol with aluminum ion in pH 4.4 HAc-NaAc buffer to form a fluorescent Al(Ⅲ)-paeonol complex.The maximum excitation wavelength and emission wavelength of the complex were 296 nm and 455 nm,respectively.The fuorescence quantum yield of the complex was determined to be 0.053 at an excitation wavelength of 296 nm.A linear calibration curve covered the concentration range 0.017-1.2μg/mL.The method has been applied to the analysis of paeonol in medicinal crop Cynanchi Paniculati Radix(Xuchangqing),and the results demonstrated that this method can be used for quality evaluation of crude drug Xuchangqing.
基金supported by the Fujii-Otsuka International Scientific Exchange Fund from Tokushima University of Japan (795001002b)Furukawa Electronic Co., Ltd., and in part by NSFC (no. 30700151)+1 种基金Academic Innovation Incubation Program from UESTC (no. Y02018023601062)The data have been published in Journal of Colloid and Interface Science (2009, 331: 507-513)
文摘Porous silica nanocapsules with 20% 3-aminopropyltrimethoxysilane (APS)-bound 6-carboxy-fluorescein (APS-fluorescein) and 80% APS molecules adsorbed on the surface
基金supported by the Natural Science Foundation of Hubei Province (2018CFB323)。
文摘Two novel macrocyclic Schiff base complexes[LnL(PhCOO)(CH3OH)](ClO4)2·(CH3OH)2(Ln=Ho,1;Ln=Er,2),in which L denotes the macrocyclic ligand,were synthesized via condensation of 2,6-diformyl-4-methyl-phenol and 1,3-diamino-2-propanol by employing benzoate as the second ligand.Their crystal structures were determined by X-ray diffraction,which showed that both complexes belong to a monoclinic system with space group P21/c.The coordination polyhedron displayed a distorted bicapped trigonal prism with the coordination number of eight.Both complexes efficiently cleaved supercoiled DNA to its nicked circular form.The UV-vis absorption results and ethidium bromide(EB)fluorescence spectra indicated that the complexes bind to CT-DNA in an intercalative mode,with Ksq values to be 11830 and 10560,respectively.
基金sponsored by the National Natural Science Foundation of China(No.31701685)Educational Commission of Anhui Province(KJ2021A1071)Chuzhou Municipal Science and Technology(Nos.2021GJ011,2021ZD017),China.
文摘A metalloporphyrin-based fluorescent sensor was developed to determine the acid value in frying oil.The electronic and structural performances of iron tetraphenylporphyrin(FeTPP)were theoretically investigated using time-dependent density functional theory and density functional theory at the B3LYP/LANL2DZ level.The quantified FeTPP-based fluorescent sensor results revealed its excellent performance in discriminating different analytes.In the present work,the acid value of palm olein was determined after every single frying cycle.A total of 10 frying cycles were conducted each day for 10 consecutive days.The FeTPP-based fluorescent sensor was used to quantify the acid value,and the results were compared with the chemical data obtained by conventional titration method.The synchronous fluorescence spectrum for each sample was recorded.Parallel factor analysis was used to decompose the three-dimensional spectrum data.Then,the support vector regression(SVR),partial least squares,and back-propagation artificial neural network methods were applied to build the regression models.After the comparison of the constructed models,the SVR models exhibited the highest correlation coefficients among all models,with 0.9748 and 0.9276 for the training and test sets,respectively.The findings suggested the potential of FeTPP-based fluorescent sensor in rapid monitoring of frying oil quality and perhaps also in other foods with higher oil contents.